It looks like while Steam updated most GCF files to the new format, some GCF files still exist in the old format. Timo was good to point out that the version change has made a versioning number in the GCF file's header quite obvious. GCFScape v1.1.3 Beta adds support for both versions five and six so those of you who were getting errors can now rest easy.

You can download the latest GCFScape here and view its revisions here.

I apologize for the massive amount of recent updates, with any luck this will be the last until Valve decides to change the format again.

id just like to point out that the reason the .gcf files keep being changed is because people were using them to play the games they correspond to. for example, people were using gcfscape to get all of the files for condition zero and moving them so it showed up as a third party game thus allowing them to play without a CD key.

you cant play online with the extracted CZ, only the single player game, and if you do try that, you cant get the latest maps, (unless you know some of my russian sources), i pay for all my valve games

i'd payed too for cz, but the russians figured out many ways to play cz for free. for example, they found a bug, how to exploit steam, so u could play cz... and you can play cz as 3rd party game online. i already tested it with my sec account.

nem, what do you think about, that the russians use your tools to make illegal versions of cz and so on?
also, they figured out how to play with this versions of cs online (non-steam servers) without a valid valvekey...

Obviously that wasn't my intent, CZ wasn't even out when I made GCFScape so I had no idea how they would distribute it.

GCF files are just a level of obfuscation and a pretty week one at that. Why do you think every game worth cracking has been cracked? The answer is because it isn't a hard thing to do, it's just a time consuming thing to do. It all comes down to ones and zeros and all you have to do to crack an application is to figure out which ones to change. It would be easy to hard code Steam not to run CZ as a third party application, but it would also be easy to crack that.

There are some files in some .gcf files that are 0 bytes big....
When you try to extract them it says Error writing "filename" (no physical data to write).
What about removing that and allow it to extract them !? Since Some games simply wonīt run without them !

You GCF file probably isn't fully acquired (as in you haven't downloaded all the files in your GCF file yet). There are very few file formats that are valid when they are 0 bytes in length; in fact, probably only text based formats are valid.

Give me some examples of the files you have that are 0 bytes in length and maybe I can provide more insight.